01/21/09
Ariba Mahmud
Math 7C
Notes: ~ I want to use percents when comparing part to whole.
~ I want to use scaling/ratio when comparing part to part.
Big Idea: Many important practical and mathematical applications involve comparing quantities of one kind or another; it is important to know which method to use and how we should use them.
Essential Question: What methods are there for comparing things?
A. Why don't the numbers in the columns add to given totals?
The numbers in the columns don't add to the given totals because most people belong in more than one category. For example, it is possible for males to participate in all activities (bicycle riding, camping, exercise walking, fishing, and swimming) and not only one.
B. Write 3 statements that use percents to make comparisons about the numbers of male and female participants in the various activities. Explain how you found the percents.
About 19% of the females participated in bike riding. About 21% of the males participated in bike riding.
About 12% of the females participated in fishing. About 27% of the males participated in fishing.
About 28% of the females participated in swimming. About 24% of the males participated in swimming.
My method was to divide number of participants in each activity by the total and then to round if necessary.
C. Write 3 statements that use percents to make comparisons about the numbers of teenage and older-adult participants.
About 41% of the teenagers participated in bike riding. About 9% of the older-adults participated in bike riding.
About 13% of the teenagers participated in exercise walking. About 37% of the older-adults participated in exercise walking.
About 51% of the teenagers participated in swimming. About 13% of the older-adults participated in swimming.
My method was to divide the number of participants in each activity by the total and to round if necessary.
D. Write 3 statements that make comparisons about data without using percents.
The ratio if males who participated in biking to females who participated in biking is 24,562,000 to 23,357,000. (ratio)
22,319,000 more females exercise walk than males. (difference)
The number of females who swim is about 1.21 times bigger than the number of males who swim. (scaling)
Follow Up
Sport
Boys
Girls
Dodgeball
8
1
Soccer
8
3
Running
8
3
Basketball
8
3
Badminton
10
3
Total
42
13
1) Explain how you might decide when percents would be a good way to make a comparison and when other forms of comparison would be better. Use examples if they help explain your ideas.
When comparing part to whole, percents would be the best way to make comparisons. For example, 45% of the 60 swimmers won medals. When comparing part to part, scaling or using ratios would be better. For example, the ratio of students to teachers is 100 to 25.
2) Can you compare the participation of teenage boys in these activities to the participation of older-adult women by using the data in the table? Explain.
You can't compare teenage boys to older-adult women because these 2 categories are not included in the table. The categories were just teenagers and older-adults; they were not divided by gender.
Problem 2.1 Comparing Leisure Activities
01/21/09Ariba Mahmud
Math 7C
Notes: ~ I want to use percents when comparing part to whole.
~ I want to use scaling/ratio when comparing part to part.
Big Idea: Many important practical and mathematical applications involve comparing quantities of one kind or another; it is important to know which method to use and how we should use them.
Essential Question: What methods are there for comparing things?
A. Why don't the numbers in the columns add to given totals?The numbers in the columns don't add to the given totals because most people belong in more than one category. For example, it is possible for males to participate in all activities (bicycle riding, camping, exercise walking, fishing, and swimming) and not only one.
B. Write 3 statements that use percents to make comparisons about the numbers of male and female participants in the various activities. Explain how you found the percents.
- About 19% of the females participated in bike riding. About 21% of the males participated in bike riding.
- About 12% of the females participated in fishing. About 27% of the males participated in fishing.
- About 28% of the females participated in swimming. About 24% of the males participated in swimming.
My method was to divide number of participants in each activity by the total and then to round if necessary.C. Write 3 statements that use percents to make comparisons about the numbers of teenage and older-adult participants.
- About 41% of the teenagers participated in bike riding. About 9% of the older-adults participated in bike riding.
- About 13% of the teenagers participated in exercise walking. About 37% of the older-adults participated in exercise walking.
- About 51% of the teenagers participated in swimming. About 13% of the older-adults participated in swimming.
My method was to divide the number of participants in each activity by the total and to round if necessary.D. Write 3 statements that make comparisons about data without using percents.
Follow Up
1) Explain how you might decide when percents would be a good way to make a comparison and when other forms of comparison would be better. Use examples if they help explain your ideas.
When comparing part to whole, percents would be the best way to make comparisons. For example, 45% of the 60 swimmers won medals. When comparing part to part, scaling or using ratios would be better. For example, the ratio of students to teachers is 100 to 25.
2) Can you compare the participation of teenage boys in these activities to the participation of older-adult women by using the data in the table? Explain.
You can't compare teenage boys to older-adult women because these 2 categories are not included in the table. The categories were just teenagers and older-adults; they were not divided by gender.